Magnesium Flashcards
How is Mg typically found in the body?
bound to other ligands and molecules
How is Mg involved in glycolysis?
Mg improves the 3D stability of high energy molecules such as ATP in order to facilitate the transfer of phosphate between groups
It is also involved in stabilizing proteins, enzymes and other nucleic acids
Magnesium is the _______ most abundant cation in the body.
4th
What is the second most abundant intracellular cation?
Mg
What type of molecule does magnesium have a high affinity for?
Charged molecules
True or False: Magnesium can bind to highly charged anions that other cations cannot.
True
What is the majority location of magnesium in the body?
Intracellular
What percentage of magnesium is found in plasma?
1%
Name general functions of magnesium.
- Energy metabolism
- Nucleic acid and protein synthesis
- Second messenger systems
- Ion channel function
How does Mg impact Nucleic acids and protein synthesis?
Mg binds to phoshate groups on nucleic acids and shields it from degradation or binding of other molecules
-increases stability of double helix
In glycolysis, Mg²⁺ stabilizes intermediates during which steps?
- Step 1: Glucose → Glucose-6-phosphate
- Step 3: Fructose-6-phosphate → Fructose-1,6-bisphosphate
- Step 7: 1,3-BPG → 3-Phosphoglycerate
- Step 9: 2-Phosphoglycerate → Phosphoenolpyruvate
- Step 10: Phosphoenolpyruvate → Pyruvate
What is the function of Mg²⁺ in the phosphoinositol?
1) provides phospholipid substrate for PIP2 reaction
2) Mg-ATP drives protein kinase C
What role does Mg²⁺ play in adenylate cyclase activity?
1) Activation of G sub-units
2) Enhances G-protein activity
3) Required for ATP
True or False: Mg²⁺ is not required for ribosome function.
False
What is the role of Mg²⁺ in second messenger systems?
Enhances G-protein signaling
What does Mg²⁺ stabilize in the phosphoinositol cycle?
Reaction of phospholipase C hydrolyzing PIP₂
what impact does Mg have on ion channels?
1) needed for active transport of K+ out of cells (Na+/K+ pump)
2) ATP synthase needs Mg2+ activity
3) passive K+ channels
-direct effct on conformation of K+ channels
What effect does Mg²⁺ have on muscle contraction?
Promotes relaxation
What is the general overview of magnesium in the diet?
Magnesium is widely available in foods, and deficiency from diet alone is rare. Levels vary depending on processing and preparation.
What are high dietary sources of magnesium?
- Legumes (beans, lentils, peas)
- Green leafy vegetables (spinach, kale)
- Nuts & Seeds (almonds, cashews, pumpkin seeds)
- Whole grains (unpolished grains, brown rice, oats)
What are moderate dietary sources of magnesium?
- Meats
- Fruits
- Dairy products (milk, cheese, yogurt)
- Chocolate & Beverages
How does water source affect magnesium levels?
Hard water contains higher magnesium levels, while water softening can reduce magnesium content.
How can magnesium deficiency be related to exercise?
Magnesium deficiency can be seen in individuals who exercise regularly due to increased sweat loss and energy metabolism.
What is the basis for magnesium intake recommendations for breastfed infants?
AI (Adequate Intake) based on magnesium content in breast milk and solid foods.
